High critical-current density and scaling of phase-slip processes in YBaCuO nanowires

YBaCuO nanowires were reproducibly fabricated down to widths of 50 nm. A Au/Ti cap layer on YBCO yielded high electrical performance up to temperatures above 80 K in single nanowires. Critical current density of tens of MA/cm2 at T = 4.2 K and of 10 MA/cm2 at 77 K were achieved that survive in high magnetic fields. Phase-slip processes were tuned by choosing the size of the nanochannels and the intensity of the applied external magnetic field. Data indicate that YBCO nanowires are rather attractive system for the fabrication of efficient sensors, supporting the notion of futuristic THz devices.Comment: 8 pages, 3 figures. Accepted for publication in Superconductor Science and Technolog

Geometrical vortex lattice pinning and melting in YBaCuO submicron bridges

Since the discovery of high-temperature superconductors (HTSs), most efforts of researchers have been focused on the fabrication of superconducting devices capable of immobilizing vortices, hence of operating at enhanced temperatures and magnetic fields. Recent findings that geometric restrictions may induce self-arresting hypervortices recovering the dissipation-free state at high fields and temperatures made superconducting strips a mainstream of superconductivity studies. Here we report on the geometrical melting of the vortex lattice in a wide YBCO submicron bridge preceded by magnetoresistance (MR) oscillations fingerprinting the underlying regular vortex structure. Combined magnetoresistance measurements and numerical simulations unambiguously relate the resistance oscillations to the penetration of vortex rows with intermediate geometrical pinning and uncover the details of geometrical melting. Our findings offer a reliable and reproducible pathway for controlling vortices in geometrically restricted nanodevices and introduce a novel technique of geometrical spectroscopy, inferring detailed information of the structure of the vortex system through a combined use of MR curves and large-scale simulations

Genetics of intellectual disability in consanguineous families

Autosomal recessive (AR) gene defects are the leading genetic cause of intellectual disability (ID) in countries with frequent parental consanguinity, which account for about 1/7th of the world population. Yet, compared to autosomal dominant de novo mutations, which are the predominant cause of ID in Western countries, the identification of AR-ID genes has lagged behind. Here, we report on whole exome and whole genome sequencing in 404 consanguineous predominantly Iranian families with two or more affected offspring. In 219 of these, we found likely causative variants, involving 77 known and 77 novel AR-ID (candidate) genes, 21 X-linked genes, as well as 9 genes previously implicated in diseases other than ID. This study, the largest of its kind published to date, illustrates that high-throughput DNA sequencing in consanguineous families is a superior strategy for elucidating the thousands of hitherto unknown gene defects underlying AR-ID, and it sheds light on their prevalence

Brixsino High-Flux Dual X-Ray and THz Radiation Source Based on Energy Recovery Linacs

We present the conceptual design of a compact light source named BriXSinO. BriXSinO was born as demonstrator of the Marix project, but it is also a dual high flux radiation source Inverse Compton Source (ICS) of X-ray and Free-Electron Laser of THz spectral range radiation conceived for medical applications and general applied research. The accelerator is a push-pull CW-SC Energy Recovery Linac (ERL) based on superconducting cavities technology and allows to sustain MW-class beam power with almost just one hundred kW active power dissipation/consumption. ICS line produces 33 keV monochromatic X-Rays via Compton scattering of the electron beam with a laser system in Fabry-Pérot cavity at a repetition rate of 100 MHz. The THz FEL oscillator is based on an undulator imbedded in optical cavity and generates THz wavelengths from 15 to 50 micron

Techno-economic assessment of the pyrolysis of rubber waste

Slow rubber pyrolysis was performed at 300–500 ◦C in a horizontal batch mechanically fluidized reactor with 30–60 min holding time, and the products were characterized. The char (yield = 50%-wt) exhibited a high heating value (HHV) around 30 MJ/kg, comparable with bituminous coke, and 84%-wt Carbon. The gas products (yield = 24–31%) had a composition dependent on temperature: 21%-v ethylene, 46%-v propane, and 11%-v butane at 300 ◦C; over 20%-v hydrogen and methane at 400 ◦C; at 500 ◦C hydrogen ranged 46-69%-v and methane 21-36%-v. Oil products (yield = 17–22% yield) consisted o

Feasibility of a High Temperature Superconductor rf-SQUID based on Biepitaxial Josephson Junction Technology

Recently, the observation of macroscopic quantum effects in high critical temperature superconductor (HTS) Josephson junctions (JJs) paved the way to the possible use of HTS in quantum hybrid circuits. Dissipation in HTS JJs has been proven to be below expectations, even in junction configurations designed to fully exploit the functionality of a d-wave order parameter symmetry, where low energy quasi-particles can be more harmful for coherence. We report on the design of YBaCuO rf-SQUIDs based on the properties of sub-micron biepitaxial junctions with variable interface orientation with respect to the order parameters of the two electrodes. The study of the double well potential of such system may offer further insights for a deeper understanding of the dynamics of a HTS Josephson device. The rf-SQUID has been designed to have independent controls for the barrier height between the wells and for the relative positions of the energy levels in different fluxoid wells. The flux state of the rf-SQUID is readout by an inductively coupled dc-SQUID magnetometer

Dynamics of vortex matter in YBCO sub-micron bridges

We have developed a fabrication process that allows us to realize pure YBCO nanowires displaying robust superconductivity at widths w as low as 160 nm. We can modify the process in order to maintain a Au protective layer. This allows us to scale our nanowires even further to widths as low as 50 nm. We have studied how the presence of vortices and the occurrence of phase slips affect the transport properties of nanowires in the width range xi < w < lambda, being xi the coherence length and lambda the magnetic penetration depth. Magnetoresistance curves present features which are related to the effect of screening currents. Vortex entry barrier is found to scale with the width. Our findings confirm that for widths xi < w < lambda nanowires are better protected against phase slips and vortex flow

Glass Patterns and Artistic Imaging

The theory of Glass patterns naturally combines three essential aspects of painterly artworks: perception, randomness, and geometric structure. Therefore, it seems a suitable framework for the development of mathematical models of the visual properties that distinguish paintings from photographic images. With this contribution, we introduce a simple mathematical operator which transfers the microstructure of a Glass pattern to an input image, and we show that its output is perceptually similar to a painting. An efficient implementation is presented. Unlike most of the existing techniques for unsupervised painterly rendering, the proposed approach does not introduce 'magic numbers' and has a nice and compact mathematical description, which makes it suitable for further theoretical analysis. Experimental results on a broad range of input images validate the effectiveness of the proposed method in terms of lack of undesired artifacts, which are present with other existing methods, and easy interpretability of the input parameters